Description
You are looking at a polished piece of “Schalenblende”, the reniform and botryoidal arrangements of alternating layers of Wurtzite and Sphalerite. The color is a variety of shades of beige to dark brown. One side is slabbed and polished while the “back” is polished under retention of its original shape. A classic Belgian specimen form the Schmalgraf Mine, which mined Lead-Zink ores from 1867 to 1931.